United States. Department of Agriculture. Economic Research Service. (1994). Agricultural resources and environmental indicators. The Service.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रUnited States. Department of Agriculture. Economic Research Service. Agricultural Resources and Environmental Indicators. Washington, DC: The Service, 1994.
एमएलए (9वां संस्करण) प्रशस्ति पत्रUnited States. Department of Agriculture. Economic Research Service. Agricultural Resources and Environmental Indicators. The Service, 1994.
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